ELECTROOSMOTIC MIXING INDUCED BY NON-UNIFORM ZETA POTENTIAL AND APPLICATION FOR DNA MICROARRAY IN MICROFLUIDIC CHANNEL

In this study, we describe a modification of the conventional microarray format. 20-mer oligonucleotide probes and singly labeled 20-mer targets, representative of the T-cell acute lymphocytic leukemia 1 (TAL1) gene, has been used to elucidate the performance of this hybridization approach. DNA microarray is integrated with microfluidic channel on a poly(methyl methacrylate) (PMMA) to generate non-uniform zeta potential inside the channel. A microtrench is designed and fabricated on a PMMA chip using a widely available CO2 laser scriber The electroosmotic mixing effect induced by the non-uniform zeta potential is utilized to enhance the DNA-DNA hybridization. The flow field in microfluidic channel is measured by particle image velocimetry (PIV). The enhanced signal to noise (S/B) ratio and reduced hybridization time is observed when the electroosmotic mixing is applied in the DNA-DNA hybridization.

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Flow Field Analysis of Dielectrophoretically-Suspended Particles

Volume 11: Micro and Nano Systems, Parts A and B ◽

10.1115/imece2007-41252 ◽

2007 ◽

Author(s):

Stuart J. Williams ◽

Steven T. Wereley

Keyword(s):

Electric Fields ◽

Particle Image ◽

Fluid Velocity ◽

Microfluidic Channel ◽

Velocity Fields ◽

Field Analysis ◽

Tracer Particles ◽

Image Velocimetry ◽

Flow Field Analysis ◽

Complete Investigation

Understanding the fluid dynamics around a particle in suspension is important for a complete investigation of many hydrodynamic phenomena, including microfluidic models. A novel tool that has been used to analyze fluid velocity fields in microfluidics is micro-resolution particle image velocimetry (μPIV) [1]. Dielectrophoresis (DEP) is a technique that can translate and trap particles by induced polarization in the presence of nonuniform electric fields. In this paper, DEP has been used to capture and suspend a single 10.1μm diameter spherical particle in a microfluidic channel. μPIV is then used with smaller tracer particles (0.5μm) to investigate the hydrodynamics of fluid flow past the trapped particle.

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Hydrodynamic Investigations of a Dielectrophoretically Trapped and Agitated Microparticle

Volume 2: Fora ◽

10.1115/fedsm2009-78068 ◽

2009 ◽

Author(s):

Stuart J. Williams ◽

Steven T. Wereley

Keyword(s):

Fluid Dynamics ◽

Particle Image Velocimetry ◽

Spherical Particle ◽

Electric Fields ◽

Particle Image ◽

Suspended Particle ◽

Microfluidic Channel ◽

Induced Polarization ◽

Image Velocimetry ◽

Complete Investigation

Understanding the fluid dynamics of a particle in suspension is important for a complete investigation of many hydrodynamic phenomena, including microfluidic models. Dielectrophoresis (DEP) is a technique that can translate and trap particles through induced polarization when in the presence of non-uniform electric fields. Here, DEP has been used to capture and suspend a single 10.1 μm diameter spherical particle in a microfluidic channel. Procedures and results for controlled, oscillatory dielectrophoretic agitation of the suspended particle are shown. Hydrodynamic investigations are discussed including the incorporation of micron-resolution particle image velocimetry (μPIV).

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Identification of hydrodynamic forces around 3D surrogates using particle image velocimetry in a microfluidic channel

Microfluidics, BioMEMS, and Medical Microsystems XVI ◽

10.1117/12.2290372 ◽

2018 ◽

Author(s):

Shubhankar Nath ◽

Utkan Demirci ◽

Tayyaba Hasan ◽

Giuliano Scarcelli ◽

Imran Rizvi ◽

...

Keyword(s):

Particle Image Velocimetry ◽

Particle Image ◽

Microfluidic Channel ◽

Hydrodynamic Forces ◽

Image Velocimetry

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Motility of leukemic lymphocytes

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100159382 ◽

1990 ◽

Vol 48 (3) ◽

pp. 368-369

Author(s):

Manoj Raje ◽

Karvita B. Ahluwalia

Keyword(s):

Quantitative Data ◽

Laser Doppler Velocimetry ◽

Acute Lymphocytic Leukemia ◽

Lymphocytic Leukemia ◽

Cellular Space ◽

Differentiated Cells ◽

Poorly Differentiated ◽

Solid Tissues ◽

Well Differentiated ◽

Reduced Mobility

In Acute Lymphocytic Leukemia motility of lymphocytes is associated with dissemination of malignancy and establishment of metastatic foci. Normal and leukemic lymphocytes in circulation reach solid tissues where due to in adequate perfusion some cells get trapped among tissue spaces. Although normal lymphocytes reenter into circulation leukemic lymphocytes are thought to remain entrapped owing to reduced mobility and form secondary metastasis. Cell surface, transmembrane interactions, cytoskeleton and level of cell differentiation are implicated in lymphocyte mobility. An attempt has been made to correlate ultrastructural information with quantitative data obtained by Laser Doppler Velocimetry (LDV). TEM of normal & leukemic lymphocytes revealed heterogeneity in cell populations ranging from well differentiated (Fig. 1) to poorly differentiated cells (Fig. 2). Unlike other cells, surface extensions in differentiated lymphocytes appear to originate by extrusion of large vesicles in to extra cellular space (Fig. 3). This results in persistent unevenness on lymphocyte surface which occurs due to a phenomenon different from that producing surface extensions in other cells.

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